When a user writes a processing program in a general computerized numerical control (CNC) machine tool, the ability to write a program that is not only capable of processing simple shapes but also complicated and varied shapes is required. Because it is very difficult for a user to directly program machine commands in order to process a complicated shape, a device for automatically programming machine commands is required, and this device is a tool path automatic forming device. The processing know—how of a machine user is contained in this device, and currently, not only is the tool path forming function included, but functions such as those for detecting tool collisions and unmilled areas are also included.
Meanwhile, for this tool path for milling, because interference regions necessarily arise in which processing is actually not possible due to the tool angles of tools, a method of forming a tool path that avoids interference regions is required.
However, methods of forming a tool path for milling in the related art are mostly methods for forming a tool path formed in only a straight line in order to avoid interference regions.
Further, even in the case of an arc shape, because the starting point of an interference region has been considered simply as a contact point in an arc, when a starting point (P) of an interference region, as illustrated in FIG. 12, is not a contact point in an arc, but is an intersecting point, a tool forming path that avoids an interference region cannot be formed.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.